Pile drivers are mechanical devices used to drive piles, poles, I-beams, or other members into the ground or other surfaces to provide foundation support for buildings or other structures. Although pile drivers are well-established, it is always desirable to improve the speed and reliability of the equipment used. Thus, a recent innovation finding more use in the field is vibration-enhanced pile driving equipment. One example is a sonic pile driver.
Vibratory or sonic pile drivers include a sonic drill head which may be lifted and positioned over the member by a drill rig mast, excavator or crane, and then fastened to the member using threading or flanging, for example. Such pile drivers may be designed to generate mechanical oscillating forces wherein horizontal vibrations cancel out, while vertical vibrations (e.g., those most effective at improving pile driving speed and reliability) are transmitted into the member. These vibrations may be used to either drive in or extract the member, and the vibration rates may range from about 0 Hz to about 150 Hz (vibration cycles per second). To effectively and efficiently transmit the vibrations from the sonic drill head to the member, the coupling between the sonic drill head and member should be tight and secure. However, existing sonic drill heads are not optimally designed to form such a tight and secure coupling. As a result, the fastening of a sonic drill head to a member may result in poor transfer of oscillating force, or even slippage between the sonic drill head and the member.
Thus, it would be desirable to provide systems and methods to provide improved coupling of a sonic drill head to a member to transfer oscillating force thereto in a more efficient manner, thereby to improve effectiveness of all sonic pile driving applications.